Publications
(* equal contributions; † corresponding author. For an up-to-date list, please visit the Google Scholar page.)
Under review & preprints
Z. Wu, S. Cheng, P. Zhao, A. Gahlawat, K. A. Ackerman, A. Lakshmanan, C. Yang, J. Yu, and N. Hovakimyan. “L1Quad: L1 adaptive augmentation of geometric control for agile quadrotors with performance guarantees.” Submitted to a journal, 2023. [arXiv] [video]
P. Zhao, Z. Guo, A. Gahlawat, H. Kang, and N. Hovakimyan. “Guaranteed nonlinear tracking in the presence of learned dynamics with contraction metrics and disturbance estimation.” arXiv preprint arXiv:2112.08222, 2022. [arXiv]
V. Sharma, P. Zhao, and N. Hovakimyan. “Learning tube-certified control using robust contraction metrics.” Submitted to a conference, 2023. [arXiv]
Journal papers
P. Zhao, S. Snyder, N. Hovakimyan, and C. Cao. “Robust adaptive control of linear parameter-varying systems with unmatched uncertainties.” Journal of Guidance, Control, and Dynamics, accepted, 2024. [arXiv] [code]
P. Zhao, R. Ghabcheloo, Y. Cheng, H. Abdi, and N. Hovakimyan. “Convex synthesis of control barrier functions under input constraints.” IEEE Control Systems Letters (L-CSS), pp.3102-3107, 2023. [code]
P. Zhao, I. Kolmanovsky, and N. Hovakimyan. “Integrated adaptive control and reference governors for constrained systems with state-dependent uncertainties.” IEEE Transactions on Automatic Control, 69(5):3158-3173, 2024.
S. Snyder, P. Zhao†, and N. Hovakimyan. “L1 adaptive control with switched reference models: Application to Learn-to-Fly.” Journal of Guidance, Control, and Dynamics, 2022. [video]
Y. Cheng*, P. Zhao*, F. Wang, D. J. Block, and N. Hovakimyan. “Improving the robustness of reinforcement learning policies with L1 adaptive control.” IEEE Robotics and Automation Letters, 2022. [video]
P. Zhao, A. Lakshmanan, K. Ackerman, A. Gahlawat, M. Pavone, and N. Hovakimyan. “Tube-certified trajectory tracking for nonlinear systems with robust control contraction metrics.” IEEE Robotics and Automation Letters, 2022. [extended version] [video] [code]
P. Zhao, Z. Guo, and N. Hovakimyan. “Robust nonlinear tracking control with exponential convergence using contraction metrics and disturbance estimation.” Sensors, 2022.
S. Snyder, P. Zhao, and N. Hovakimyan. “Adaptive control for linear parameter-varying systems with application to a VTOL aircraft.” Aerospace Science and Technology, 2021.
Y. Mao, H. Jafarnejadsani, P. Zhao, E. Akyol and N. Hovakimyan. “Novel stealthy attack and defense strategies for networked control systems.” IEEE Transactions on Automatic Control, 2020.
A. Alizadegan, P. Zhao, R. Nagamune and M. Chiao. “Experimental validation of a robust H∞ control method on miniaturized optical image stabilizer prototypes.” Journal of Dynamic Systems, Measurement, and Control, 2020.
P. Zhao and R. Nagamune. “Switching linear parameter-varying control with improved local performance and optimized switching surfaces.” International Journal of Robust and Nonlinear Control, 2018. [code]
P. Zhao and R. Nagamune. “Multiple parameter-dependent robust control of miniaturized optical image stabilizers.” Control Engineering Practice, 2018.
A. Alizadegan, P. Zhao, R. Nagamune, and M. Chiao. “Robust H∞ control of miniaturized optical image stabilizers against product variabilities.” Control Engineering Practice, 2018.
P. Zhao and R. Nagamune. “Switching LPV controller design under uncertain scheduling parameters.” Automatica, 2017. [code]
X. Wang, S. Wang, and P. Zhao. “Adaptive fuzzy torque control of passive torque servo systems based on small gain theorem and input-to-state stability.” Chinese Journal of Aeronautics, 2012.
Book chapter
K. Yuan, A. Alizadegan, P. Zhao, R. Nagamune, J. Chu, S. Park, and M. Chiao. “Design, fabrication, and robust control of miniaturized optical image stabilizers.” Advanced Mechatronics and MEMS Devices II, 2017
Conference proceedings
R. Tao, P. Zhao, I. Kolmanovsky, and N. Hovakimyan. “Robust Adaptive MPC using uncertainty compensation.” 2024 American Control Conference, accepted, 2024. [arXiv]
R. Tao, P. Zhao, J. Wu, N. F. Martin, M. T. Harrison, C. Ferreira, Z. Kalantari, and N. Hovakimyan. “Optimizing Crop management with reinforcement learning and imitation learning.” Proceedings of the Thirty-Second International Joint Conference on Artificial Intelligence (IJCAI-23), pp. 6228-6236, 2023.
Y. Cheng*, P. Zhao*, and N. Hovakimyan. “Safe model-free reinforcement learning using disturbance-observer-based control barrier functions.” 5th Conference on Learning for Dynamics and Control, 2023. [video]
L. Song, Y. Li, S. Cheng, P. Zhao, S. Mitra, N. Hovakimyan. Verification of L1 adaptive control using Verse library: A case study of quadrotors. Proceedings of the ACM/IEEE 14th International Conference on Cyber-Physical Systems (with CPS-IoT Week 2023), pp. 245-246, 2023.
L. Song, P. Zhao, N. Wan, and N. Hovakimyan. “Safety embedded stochastic optimal control of networked multi-agent systems.” American Control Conference (ACC), pp. 2554-2559, 2023.
C. Aoun, P. Zhao, H. Almubarak, N. Hovaimyan, and E. Theodorou. “L1 adaptive control of constrained systems using barrier states.” AIAA SciTech Forum, 2023.
Z. Wu, C. Sheng, K. A. Ackerman, A. Gahlawat, A. Lakshmanan, P. Zhao, and N. Hovakimyan. “L1 adaptive augmentation for geometric tracking control of quadrotors.” IEEE International Conference on Robotics and Automation (ICRA), 2022. [video] [code]
Wu*, R. Tao*, P. Zhao*, N. Martin, and N. Hovakimyan. “Optimizing nitrogen management with deep reinforcement learning and crop simulations.” IEEE/CVF Conference on Computer Vision and Pattern Recognition Workshops, 2022. [arXiv]
A. Gahlawat, P. Zhao, A. Patterson, N. Hovakimyan, and E. A. Theodorou. “L1-GP: L1 adaptive control with Bayesian learning.” 2nd Conference on Learning for Dynamics and Control (L4DC), 2020.
P. Zhao, Y. Mao, C. Tao, N. Hovakimyan, and X.Wang. “Adaptive robust quadratic programs using control Lyapunov and barrier functions.” 59th IEEE Conference on Decision and Control, 2020.
S. Snyder, P. Zhao and N. Hovakimyan. “L1 adaptive control for switching reference systems: Application to flight control.” 11th IFAC Symposium on Nonlinear Control Systems (NOLCOS), 2019.
Y. Mao, H. Jafarnejadsani, P. Zhao, E. Akyol, and N. Hovakimyan. “Detectability of intermittent zero-dynamics attack in networked control systems.” 58th IEEE Conference on Decision and Control, 2019.
P. Zhao and R. Nagamune. “Switching LPV control of a floating offshore wind turbine on a semi-submersible platform.” 28th IEEE International Symposium on Industrial Electronics, 2019.
P. Zhao and R. Nagamune. “Discrete-time state-feedback switching LPV control with separate Lyapunov functions for stability and local performance.” American Control Conference, 2018. [code]
P. Zhao and R. Nagamune. “Optimal switching surface design for switching LPV control and its application to air-fuel ratio control of an automotive engine.” IEEE Conference on Control Technology and Applications (CCTA), 2017.
A. Alizadegan, P. Zhao, R. Nagamune, and M. Chiao. “Modeling and robust control of miniaturized magnetically-actuated optical image stabilizers.” IEEE International Conference on Advanced Intelligent Mechatronics, 2016.
P. Zhao and R. Nagamune. “ Optimal switching surface design for state-feedback switching LPV control.” American Control Conference (ACC), 2015.
P. Zhao, A. Alizadegan, R. Nagamune, and M. Chiao. “Robust control of large-scale prototypes for miniaturized optical image stabilizers with product variations.” SICE Annual Conference, 2015.
P. Zhao, S. Wang, X. Li and B. Zhang. “A novel method of parameter identification of nonlinear electro-hydraulic servo systems.” International Conference on Fluid Power and Mechatronics, 2011.
Workshop Papers and Extended Abstracts
R. Tao, P. Zhao, J. Wu, N. F. Martin, M. T. Harrison, C. Ferreira, Z. Kalantari, and N. Hovakimyan. “Optimizing Crop management with reinforcement learning and imitation learning: Extended abstract.” International Conference on Autonomous Agents and Multiagent Systems, 2023.
P. Zhao, Z. Guo, Y. Cheng and N. Hovakimyan. “Guaranteed nonlinear control with DNN-learned dynamics using robust contraction metrics and disturbance estimation.” AAAI Workshop on Trustworthy Autonomous Systems Engineering, 2022.
Y. Cheng⋆,†, P. Zhao⋆, M. Gandhi, B. Li, E. Theodorou, and N. Hovakimyan. “L1-RL:Robustifying reinforcement learning policies with L1 adaptive control.” ICRA Workshop on Safe Robot Control with Learned Motion and Environment Models, 2021.
H.-J. Yoon, P. Zhao, C. Tao, C. Widdowson, R. Wang, N. Hovakimyan, and E. Theodorou. “Socially aware motion planning for a flying robot with model predictive path integral control.” ICRA Workshop on Algorithms and Architectures for Learning-in-the-Loop Systems in Autonomous Flight, 2019.
Patents
P. Zhao, J. Xue, M. Zhang, and Z. Jia, “A method for modeling of electronic stability program (ESP) brake hydraulic systems in automobiles”, Chinese Patent 103499453 B, granted Nov 2015.
P. Zhao, L. Wan, M. Zhang and J. Xue, “Experiment platform for hardware-in-the-loop testing of electric power steering systems”, Chinese Patent 203116978 U, granted Aug 2013.